大气颗粒物PM_(2.5)附着于角膜接触镜及其对角膜接触镜透氧性及折射率的影响

Particulate matter 2.5 deposition on corneal contact lens and its effects on the oxygen permeability and refractive index of contact lenses

目的观察大气颗粒物PM_(2.5)在角膜接触镜的附着情况及其对角膜接触镜透氧性和折射率的影响。方法采集大气颗粒物PM_(2.5),配制浓度为1 mg·m L^(-1)的PM_(2.5)混悬液,取硬性透气性角膜接触镜(rigid gas permeable contact lens,RGPCL)和软性角膜接触镜(soft contact lens,SCL)各18只,分为对照组、实验组和洗脱组,每组6只。实验组和洗脱组角膜接触镜浸入PM_(2.5)混悬液中,室温振荡24 h。洗脱组经上述处理后转入无菌PBS中,室温振荡1 h。对照组镜片浸入无菌PBS中,室温振荡24 h。利用场发射扫描电子显微镜下观察PM_(2.5)在各组角膜接触镜表面的附着情况。检测各组角膜接触镜的透氧性和折射率,记录结果,并进行统计分析。结果经过PM_(2.5)混悬液浸泡后,实验组RGPCL表面发现存在较多PM_(2.5)附着,呈散在分布。实验组RGPCL表面大气颗粒物计数为每100μm^2(3.19±1.64)个。对照组电镜扫描未发现大气颗粒物沉着。经洗脱后,洗脱组RGPCL表面仍可见大量大气颗粒物附着,每100μm2(5.12±1.27)个。洗脱组与实验组差异有统计学意义(P<0.05)。实验组SCL表面,大气颗粒物集中附着在SCL水凝胶孔隙边缘,而在孔隙中未见大气颗粒物附着,大气颗粒物细小,均匀;实验组SCL表面大气颗粒物计数为每100μm^(2)(2.16±1.19)个。对照组SCL表面无大气颗粒物附着。经洗脱后,洗脱组SCL表面大气颗粒物计数为每100μm^(2)(0.56±0.39)个,洗脱组与实验组差异有统计学意义(P<0.05)。对实验组RGPCL和SCL表面大气颗粒物附着数进行比较,RGPCL表面大气颗粒物附着数较多,差异有统计学意义(P<0.05)。经过PM2.5混悬液浸泡后,实验组RGPCL的透氧性(100.00±3.17)与对照组(100.00±2.36)比较差异无统计学意义(P>0.05)。实验组SCL透氧性(42.00±2.57)与对照组(41.00±3.44)比较差异亦无统计学意义(P>0.05)。经过PM_(2.5)混悬液浸泡24 h后,实验组RGPCL的折射率(1.415 6±0.000 4)与对照组(1.415 3±0.000 4)比较差异无统计学意义(P>0.05)。实验组SCL折射率(1.373 7±0.000 7)与对照组(1.373 2±0.000 1)比较差异亦无统计学意义(P>0.05)。结论与SCL相比,PM_(2.5)更易附着在RGPCL表面,且不易洗脱。在本研究条件下,PM_(2.5)虽然附着于角膜接触镜,但短时间内并未对角膜接触镜的透氧性及折射率产生影响。

Objective To observe the deposition of PM2.5 in the contact lens and its influence on the oxygen permeability and refractive index of the contact lens.Methods Atmospheric PM2.5 was collected for preparation of 1 mg·mL^-1 PM2.5 suspension.Then,18 rigid gas permeable contact lenses （RGPCL） and 18 soft contact lens lenses （SCL） were grouped in control,experimental and PBS-rinse group,with 6 RGPCL and 6 SCL in each group.RGPCL and SCL in the experimental and PBS-rinse groups were incubated in 1 mg·mL^-1 PM2.5 solution for 24 h,followed by PBS-rinse group were further washed for 1 h in PBS,whereas the controls were incubated in PBS for 24 h.All of them were examined with field scanning electron microscopy.Meanwhile,oxygen permeability and refractive index of contact lens were measured using the polar graphic devices and refractometry respectively.All the obtained data were quantitatively and statistically analyzed.Results After treatment in PM2.5 solution,there was a large amount of PM2.5 deposition on the RGPCL surface in the experimental group,and the amount of PM2.5 was counted （3.19±1.64）·100 μm^-2,while no atmospheric particulate matter was found in the control group;following the treatment of PBS,a lot of PM2.5 attached on the surface of RGPCL remained visible,and the number of particles was （5.12±1.27）·100 μm^-2.And the difference was statistically significant between the control group and PBS-rinse group （P〈0.05）.In addition,and the amount of PM2.5 attached on the surface of SCL in the experimental group was （2.16±1.19）·100 μm^-2,while there wasn’t any atmospheric particulate matter in the control group;and,after a wash of SCL in PBS,the amount of PM2.5 on SCL surface was （0.56±0.39）·100 μm^-2 in the PBS-rinse group,indicating a statistically difference between the control group and PBS-rinse group （P〈0.05）.Moreover,the amount of PM2.5 attachment on SCL surface in the experimental group was significantly lower than that of the control group,and the difference was statistically significant （P〈0.05）.After PM2.5 solution treatment,oxygen permeability of RGPCL and SCL was 100.00±3.17 and 42.00±2.57 respectively in the experimental group,as well as 100.00±2.36 and 41.00±3.44 in the control group,with no statistically significant difference between the two groups （all P〉0.05）;while refractive index of RGPCL and SCL was 1.415 6±0.000 4 and 1.373 7±0.000 7 respectively in the experimental group,as well as 1.415 3±0.000 4 and 1.373 7±0.000 1 in the control group,with no statistically significant difference between the two groups either （all P〉0.05）.Conclusion PM2.5 can be attached to the surface of RGPCL and SCL,and PM2.5 is easier to adhere to RGPCL surface and is not easy to elute when compared with SCL,but PM2.5 deposition do not affect oxygen permeability and refractive index of contact lenses over a short span of time.